The present invention relates to an inspection system for limited access spaces and, more particularly, but not exclusively to a vehicle inspection system suitable for inspection of parts of vehicles that are awkward to inspect easily.
Vehicle underside inspection is necessary for several reasons, one being to provide security, a second being for safety and a third being for contraband detection, by customs inspectors and the like. On the security side, undersides of vehicles may have concealed explosive devices. Of particular concern is the possibility of concealing an explosive device on the underside of a fuel tanker, which device is timed or controlled to explode when the tanker is inside a fuel distribution depot. Carrying out detailed manual inspections of the undersides of each tanker entering a fuel depot is both time and labor consuming. On the safety side, the underside of the vehicle may conceal a mechanical flaw, the early detection of which may prevent an accident. In a garage or workshop a car is generally jacked up or placed on a ramp. Larger vehicles are placed on ramps or are driven over inspection pits. However, outside the garage environment, inspection of the underside of a vehicle is difficult. Contraband detection at borders by customs officials is often based on spot checks since customs very rarely have the resources to inspect every passing vehicle. Any means of allowing a more detailed inspection in a smaller time frame would be welcome.
Security checks for entry into government buildings and the like are typically carried out using a mirror on the end of a pole, which is inserted under the vehicle. However, without illumination it is difficult to see much detail and even with illumination, an explosive device can be concealed in a spot that is awkward to view using the mirror. Furthermore such a mirror is very unlikely to spot hairline cracks, which are usually the first signs of dangerous mechanical faults. It is impractical to install inspection pits at all places where regular vehicle checks are desirable.
U.S. Pat. No. 6,249,567 to Rothschild et al discloses an inspection system for inspecting a vehicle moving at a grade of travel over a surface and for detecting material disposed within or on the underside of the vehicle. The system has a source for providing a generally upward or downward pointing beam of penetrating radiation of specified cross-section so as to illuminate vehicles driven above or below the source of radiation. A detector arrangement, disposed below the grade of travel, detects radiation from the beam scattered by any material disposed on the underside of the moving vehicle and generates a scattered radiation signal that may be used for characterizing the material disposed on the underside of the vehicle. Similarly, a detector arrangement disposed above the vehicle generates a scattered radiation signal that may be used for characterizing the material disposed within the vehicle. The system however sits at a single location, requiring the vehicle to move during inspection. It cannot independently scan the vehicle underside. Furthermore, the main detection function of the system is based on x-rays, since a principle intention is to scan for the internal contents of the vehicle.
There is thus a widely recognized need for, and it would be highly advantageous to have, a vehicle inspection system devoid of the above limitations.